Have a look at the LM2576T-5, it's a switchmode 5v regulator in a TO220 package for about $2.
The NS datasheet has an example circuit for a 5v/3a regulated supply using about 5 components.
The Maxim MAX787 is similar but rated for 5v/5a if you can find some old stock.

Have a look at the LM2576T-5, it's a switchmode 5v regulator in a TO220 package for about $2.
The NS datasheet has an example circuit for a 5v/3a regulated supply using about 5 components.
The Maxim MAX787 is similar but rated for 5v/5a if you can find some old stock.

i looked at the LM2576T-5, i believe its the same one carnetix uses. Want more power!

i found a cheap way of doing th 5V thing, went to local Jaycar store and purchased a 5v 1.0amp cig plug with USB output plug, works just great and only cost $9.95 AUD

Do you guys know if I were to do it this way (opening up the USB cigarette adaptor and tapping the 5V DC), will it be able to withstand the surges during cranking and engine off?

I was thinking of cutting off the original power supply to the cigarette adaptor port and tapping it to an 'always-on' 12V unregulated, fused supply from the car batt, then I'll use this USB cigarette adaptor to 'cushion' the spikes and surges.